Method of making v belts



g- 19, 1952 D. WAUGH METHOD OF MAKING v BELTS Filed Feb. 25. 1950 HISATTORNEY Patented Aug. 19, 1952 i t eAT-E-Nr OFFICE f elhi-Wendie aytibidfifi fi fi Tlie' ".Dayton Rubber, Company, a, I corporation of Aplication February 25, 1950, Serial Nb. 146,190

a ti -a ms 1 ,I-he present invention relates-to belts and theirv methodof manufacture- I M e part u a ly itlrel-ates to, an improvedrtype.oftwrapped-molded belt and annovel method ,.for. its manufacture.Endless,lwrappedemoldedbelts of the V-type-are generally .made by.building va,,cyllndrical. .belt body one drum-.iroma plurality. ofsuperimposed layers rto giye the. .desi-reddnternal; construction of-..thebe1t.. The. resulting wbel-t body thencut into. individual.endless. v.cores by, .means. of ainclined knivesor cut squareand skivedso that the resultingendless cores, having ;a.trapezoida1 cross section,or that,.of, a truncated vertical, cone sec tion are wrapped,'v'vithrubberized 'iabric and placed .in. a, mold, aiterwhichg the mold,rag wrap ed to place the. -.assembled body. s u ture under compression.afllnwhicfl. it is. vulcan Typical ,methods. for. lbuilding ubeltsbythis, Pro- ,ciejd re are. describeddn the patent toFree'dlander No.2,336,084, dated ,December ,7, 19%,. andjto ,Kremeretcal. .No.2,356,249,, datedAuguSt, 22, 1944. Y While; the foregoing methods, havebeen very satisfactory and hailebeen widely used, to pro.- duce largequantitiesvo-f. belts,T it. hasvbeen, round.

that,v certain improvements. may. be, ,efiected in obtainingcliniformityof internal structure and Savings. in, material, .with resultantimprovement inperformanceand lower: ;.cost.-

Certaindisadvantages have-been found. tolexist inthe, practice of; themethodsreferredntoc above. Durin cuttin usin ,kn i xb es d sp ed a an anled it: has been, rfound that. slight distortion oi: thebladesmay occuronengagementv with in- 'betweenthecut sections.

It istherefore-an object. of the present invention to, provide. a noveltype lief, belt core from which a-. wrapped-,-.moldedbeltof;uniform-internal structure may be obtained. It is a further object of thepresent invention to describe a method for the manufacture ofbelt cores and wrappedmolded belts having a uniform internalconstructional id which will at-the same timeefl'ect savings of materialand economy ,offmanufacture. Other objectswill be apparent from thedescription below.

In accordance with the present invention, the

belt bodylis built upon a dimmer-mandrel in an which; a

- molding.

then built upv in the following manner:

ents. are .J'oined., The resultant j o e are. t en w app anddedlintheconvenli qn F nnel:-

en ion .isude cribed in, a ree et with. reference, to, the, accompanyingdraw ngs in Figure 1 is an elevational yiew,,,partlyin crgss sectionshowing the structure rorthetextruded trapezoidalcompression section, Il

i ur i ai' YQ fQv 'Q lsec iena l .1 illustrating the assembled beltbodyonadrum FigureB is, a cross sectionof.anfindiyidualbelt bo.dy,wit11itsouter .fabr1c wranping prior to Figure 4 .i1lustrates. in, crosssection-the, Stl'llQr tune ot.afinishedbelt'after-,molding e Asillustrated in, the aforesaid, drawinga a mandrel or belt building drum.Ll is selected-hay? ing ,a circumference corresponding to the, desiredouter, circumference of the belt, The belt beds; is

As shown in Figure 1,- the compressiqnlayer, I has been preformed in theform of astrinby ex trusion or other-Wiseand. has the shape of. a4111i,-

rality of. parallel trapezoidal. segments 3 oined, to;-

gether at their widest parallel portions,. or, bases, by" a relativelynarrow section of material as shownat 190,, Each of these trapezoidalsea,- ments isvto form a compression section or a-Qconresponding beltand; has, across section cor'r'e spending substantially to an iseseelestrapezoid.

Preferably, the segments are extruded in theform of. twoqor. moreadjacent segments and these. are arrangedon a building; drum insidetofside relationship; For example, if a drum 2% in. ;in-;length,isutilized the; compression s,ection;-may-be .ex trudedinthe form ofa-sing1e24 in widelstriprb lt ordinarilyit is more desirable 7 toextrude narrower widths in-which, case three 18 in-. str;;i ps or two 12inastrips could be -preformed -.and- ,-1aid side by sideon-the drum. Ifdesired howevergthe compression sectionmay-be extruded inthe dorm ofa -seme t nd these m e i dir du ll applied-overrth iace of the vdrumimam-abutting manner.. I The-depth of section ,1 0a, ,whichdoins the.segmentsfiogether should preferably-beat a minimum suff cient only to,facilitate, handling" thelse ments r up As.hbwn inFlgure 2,211, v layer'li lwhich may, for-v exampla ber a..-laye iogirictioned bias fabricwith a coating ta of, gumrubben on the ton manner. A cement coating maybe applied to the top surface of layer I5 before the applicationof thecompression section in order to insure adhesion.

After assembly of the respective layers on the drum, individual endlessbelt segments or cores areformed by rotating the drum while in contactwith one or more pairs of spaced vertically positioned knives I5 whichcut straight through the assembled layers. The individual segments arethen stripped from the drum and turned inside out. A' wrapping of twolayers I! and I8 of bias fabric is then applied around the core lappedat the top and bottom of the belt in the manner shown, for example, inFigure 3. ,The resulting core has a cross section departing slightlyfrom the trapezoidal due to the vertical portion Illa.

' In Figure 3, this departure is somewhat exaggeratedfor purposes ofillustration.

After. the wrapper has been applied the assembled structure is placed ina ring mold in the manner described in the aforementioned Patent No."2,33.6,084for example, and is rag wrapped forcing the uncured assemblyinto conformation with the shape of the mold. The assembly is then curedandthe 'resulting'belt will have theconstruction illustrated in Figure4. Since the mold has'theconformation of a true trapezoid, the slightdeparture from the form caused by the point of juncture ofthe extrudedsegments at Illa, is eliminated during the molding operation.

By way of example, a building drum having a circumference .of 70 in. wasutilized'in building a number of wrapped molded belts. A layer of 0.03ljgaug'e crude rubber gum stock was wound on the drum and spliced. Asingle ply of 2200 denier 5 ply rayon cord was then spun over the top ofthe gum layer. On top of the cord layer wasnext applied a layer of 0.031gauge crude rubber gum stock. On top of the last named'layer of gumstock was applied an extruded compression layerhaving the shapeillustrated in Figure l composed of 0.250 gauge crude rubber compoundedstock containing about 5% of finely dividedcellulose fibers milledtherein. This layer .was spliced in the conventional manner and theresulting belt sleeve was then cut into core sections 0.350 in. thickand 0.500 in. wide. In order to compare the results obtained by thismethod.

with conventional practice, each core segment was weighed and theresults checked with the weights of core sections produced by themethods described in the Freedlander and Kremer 'et al. patents referredto above. By the present method, 'the variation in weight was withinplus or minus 1 whereas by the previous method the variation ofindividual cores was more than plus or 1ninus'5%;.' Each segment wasthen inverted. Each endless core segment was then wrapped with 8 oz. 2ply warp and fill cotton duck, bias cut, frictioned on two sides andskim coated with natural rubber on, top. The assembled belts were thenplaced in ring molds and forced into conformation with the mold shape bytightly wrapping the. ring mold with rag cross wrap inthe usual manner.The resulting belts were found to have a uniform cross section, with thecords in uniform alignment and the volume and structure of thecompression section substantially the same in allthe belt made with thisconstruction.

The rubber stocks used are compounded with vulcanizing agents,accelerators, fillers, pigments, and the like, in the manner known tothe art.

The term rubber as used herein is intended to include both naturalrubber, and the synthetic vulcanizable rubber-like materials orelastomers,

such as conjugated diolefine polymers and c0- polymers includingbutadiene-styrene copolymer (Buna-S' or GR-S), butadiene-acrylic nitrilecopolymer (Buna-N or GRr-A) polychloroprene (neoprene), and the like. 7Iclaim: I

1. The method for the manufacture of V-type laminated belts havingtension, neutral axis and compression sections which comprisespreforming rubber material into a strip comprising a plurality ofadjacent, parallel segments adapted to constitute the compressionsections of the'belts, each segment having a cross section correspondingsubstantially to an isosceles trapezoid with the base thereof formed bya wider parallel side and the top thereofformed by a narrow parallel.

side, said segments being joined together at the base thereof; applyingtension and neutral axis layers co'mprisingrubber material to acylindrical mandrel, superimposing'said preformed strip by a widerparallel side and the top thereof formed by a narrow parallel side, saidsegments being joined togetherat the base thereof; applying arubber-containing tension section to a mandrel; applying arubber-containing neutral axis section over said tension section;applying said extruded strip over said neutral axis section withthebases of said segments adjacent thereto and superimposed thereon;cutting through the resulting structure vertically of the mandrelthroughthe juncture'of each segment with the adjacent"segment andthereby forming a plurality of endless belt 'coremembershaving a tensionsection at the bottom, an intermediate neutral axis section, and acompression section at the top; removingsaid belt core members from themandrel; inverting said members to place the narrow'side of eachcompression section segment on the inside of said belt core member;wrapping said'belt coremember with fabric and molding and vulcanizingsaid wrapped belt core members tol-tforma plurality of wrapped-moldedV-type r v DALE L. WAUGH.

REFERENCES CITED The-following references are of recordin the filed thispatent:

s'rATEs PArEnTs I.

Number Name Date "1,906,397 Meyer May 2, 1933 1,969,067 Freeman Aug. 7,1934

1. THE METHOD FOR HE MANUFACTURE OF V-TYPE LAMINATED BELTS HAVINGTENSION, NEUTRAL AXIS AND COMPRESSION SECTIONS WHICH COMPRISESPREFORMING RUBBER MATERIAL INTO A STRIP COMPRISING A PLURALITY OFADJACENT, PARALLEL SEGMENTS ADAPTED TO CONSTITUTE THE COMPRESSIONSECTIONS OF THE BELTS, EACH SEGMENT HAVING A CROSS SECTION CORRESPONDINGSUBSTANTIALLY TO AN ISOSCELES TRAPEZOID WITH THE BASE THEREOF FORMED BYA WIDER PARALLEL SIDE AND THE TOP THEREOF FORMED BY A NARROW PARALLELSIDE, SAID SEGMENTS BEING JOINED TOGETHER AT THE BASE THEREOF; APPLYINGTENSION AND NEUTRAL AXIS LAYERS COMPRISING RUBBER MATERIAL TO ACYLINDRICAL MANDREL, SUPERIMPOSING SAID PREFORMED STRIP ON SAID LAYERSWITH THE BASES OF THE SEGMENTS ADJACENT SAID NEUTRAL AXIS LAYER, ANDCUTTING THROUGH THE RESULTING ASSEMBLED STRUCTURE AT THE JUNCTURE OFEACH SEGMENT WITH THE ADJACENT SEGMENT AND THEREBY FORMING A PLURALITYOF ENDLESS LAMINATED BELT CORE MEMBERS.